SI4704-D50 Datasheet, PDF (24/34 Pages) Silicon Laboratories – BROADCAST FM RADIO RECEIVER FOR CONSUMER

Si4704/05-D50
For details on timing specifications and diagrams, refer
to Table 6, “3-Wire Control Interface Characteristics” on
page 9; Figure 4, “3-Wire Control Interface Write Timing
Parameters,” on page 9, and Figure 5, “3-Wire Control
Interface Read Timing Parameters,” on page 9.
4.17. GPO Outputs
The Si4704/05 provides three general-purpose output
pins. The GPO pins can be configured to output a
constant low, constant high, or high-Z. The GPO pins
are multiplexed with the bus mode pins or DCLK,
depending on the application schematic of the device.
GPO2/INT can be configured to provide interrupts for
seek and tune complete, receive signal quality, and
RDS.
4.18. Reset, Powerup, and Powerdown
Setting the RST pin low will disable analog and digital
circuitry, reset the registers to their default settings, and
disable the bus. Setting the RST pin high will bring the
device out of reset. A powerdown mode is available to
reduce power consumption when the part is idle. Putting
the device in powerdown mode will disable analog and
digital circuitry while keeping the bus active.
4.19. Programming with Commands
To ease development time and offer maximum
customization, the Si4704/05 provides a simple yet
powerful software interface to program the receiver. The
device is programmed using commands, arguments,
properties, and responses. To perform an action, the
user writes a command byte and associated arguments,
causing the chip to execute the given command.
Commands control an action such as powerup the
device, shut down the device, or tune to a station.
Arguments are specific to a given command and are
used to modify the command. A complete list of
commands is available in “AN332: Si47xx Programming
Guide”.
Properties are a special command argument used to
modify the default chip operation and are generally
configured immediately after powerup. Examples of
properties are de-emphasis level, RSSI seek threshold,
and soft mute attenuation threshold. Responses provide
the user information and are echoed after a command
and associated arguments are issued. All commands
provide a one-byte status update indicating interrupt
and clear-to-send status information. For a detailed
description of the commands and properties for the
Si4704/05, see “AN332: Si47xx Programming Guide”.
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Rev. 1.0